Correlation of spirometry and body plethysmography during exercise-induced bronchial obstruction

Abstract Background The exercise challenge is the gold standard for diagnosing exercise-induced bronchoconstriction(EIB). Airway obstructions appear up to 30 min after the challenge, with a maximum decrease in spirometryand a maximum increase in airway resistance. There is evidence that changes in body plethysmography parameters are more sensitive to the exercise challenge and precede those in spirometry. Purpose To compare changes in body plethysmography and spirometryparameters after exercise challenges and to verify the cut-off values of sReff in EIB. Procedures In 82 subjects with suspected EIB, a total of 473 lung function tests were measured at baseline and at 5, 10, 15, and 30 min after exercise challenges at different stages of bronchial obstruction. Findings The maximum changes in the body plethysmography parameter sReff significantly preceded the maximum changes in the spirometryparameter FEV 1 (sReff: 12.2 min ±8.8, FEV 1 : 15.2 min ±9.3, p  1 had a strong negative correlation (r = −0.63, p  1 and sReff almost equally detected EIB. Conclusion The changes in sReff were more sensitive and better indicated lung impairment than did the changes in FEV 1 , which underestimated the degree of hyperinflation.